The present invention relates generally to apparatus and devices for monitoring and calculating the efficiency of operation of textile machines, e.g. circular knitting machines.
In the manufacture of textile fabric, the operating efficiency of the fabric producing machinery is considered to be perhaps the single most important factor in evaluating the productivity and performance level of the machinery. Ordinarily, operating efficiency is calculated numerically for each individual manufacturing machine as a percentage value representing, for a selected time period such as an 8-hour manufacturing shift, the proportion of such time period the machine was in actual operation. The optimal goal, of course, is to maintain each manufacturing machine in continuous uninterrupted operation without stoppage for the duration of the selected time period, thereby representing a 100% efficiency. In actual practice, ordinary machine down time for machine repair, removal of finished product, replenishment of manufacturing materials and similar reasons keeps operating efficiency below this optimal level. For example, in the operation of circular knitting machines, the machine operator must periodicially stop the operation of the machine to remove, or "doff," the knitting fabric produced by the machine. Such machines also include conventional stop motion devices which automatically stop operation of the machine in the event of feed yarn breakages which require repair. Broken knitting needles and like occurrences requiring more complex repair of the machine may necessitate more extended machine down time.
The calculated operating efficiency of textile machines enables supervisory personnel to gather a statistical basis over time for comparative evaluation of differing machines and machine operators and, in turn, to identify and correct problem areas. Historically, efficiency records have been gathered by manual time studies of individual machines and machine operators, which process is disadvantageously highly labor intensive and therefore expensive. Furthermore, this process is entirely impractical for developing a shift-to-shift or even day-to-day study of machine and machine operator efficiencies and, accordingly, manual time studies are used only on a periodic basis, which detracts from the accuracy and usefulness of the information.
With the advent in recent years in increasing usage of computers in the textile industry, computerized efficiency monitoring systems have been developed for providing the continuous and systematic gathering of efficiency information on a machine-by-machine basis. Typically such efficiency monitoring systems provide a centralized monitoring station, usually located in a separate room adjacent the actual manufacturing area, whereat a personal business computer with associated peripheral CRT monitor, keyboard, software disc drive, printer and the like are located. The computer is individually connected by a network of electrical wiring with each textile machine in the manufacturing area, the operating software being adapted to continuously monitor various factors affecting efficiency and to provide continuous or periodic printouts reflecting such factors as well as the computed operating efficiency. Representative examples of such an efficiency monitoring system are manufactured and sold by Uniwave, Inc., of Farmindale, N.Y., under the model designations CPM II and Central Monitor III.
While these monitoring systems provide substantial advantages over manual time study evaluation of operating efficiency, these systems are prohibitively expensive for a large majority of textile mills. Furthermore, the remote location of the actual monitoring equipment away from the machines being monitored prevent the machine operators from obtaining an ongoing indication of the performance and productivity of the machines for which they are responsible, which information could be utilized to take immediate corrective action as well as to provide a psychological incentive to attempt to obtain the optimal practical efficiency from the machines. Instead, the data generated by these conventional computerized monitoring systems is ordinarily utilized essentially only "after the fact" to evaluate past performance, which in the case of problem areas can have a negative psychological impact on the machine operator. Additionally, these computerized monitoring systems produce a considerable volume of information which is time-consuming and somewhat difficult to analyze and may be impractical for supervisory personnel to fully evaluate and utilize on a day-to-day basis.
It is accordingly an object of the present invention to provide an inexpensive, compact, self-contained efficiency monitoring and computing device adapted to be mounted directly on a single respective textile machine for dedicated use in connection therewith to provide the machine operator and supervisory personnel with continuous, immediately available readings of operating efficiency and several closely related efficiency factors.